This invention relates to resoles containing one or more metal atoms in the polymer chain.
A reimpregnation resin is a thermosetting polymer introduced as a liquid into the characteristic void of a carbon/carbon composite. The resin is subsequently cured and heat treated, thus increasing the density of the composite. Selected polymers impart specific desired characteristics to the composite depending upon the ultimate application. Viable reimpregnation resins must maintain a suitably low viscosity during the reimpregnation process and, in addition, exhibit a relatively high char yield.
U.S. Pat. No. 4,185,043 to Robert C. Shaffer discloses thermoplastic and thermosetting polymers which incorporate tungsten and/or molybdenum metal atoms. The metal atoms are incorporated into the polymer by reacting a monomer or polymer containing at least one free carboxyl group with a reaction product of tungsten or molybdenum carbonyl and pyrrolidine to obtain a polymer. It is disclosed that the polymers are useful as reimpregnation resins.